GANDHINAGAR INSTITUTE OF TECHNOLOGY THEORY OF MACHINES FRICTIONAL CLUCHES
1. GANDHINAGAR INSTITUTE OF
TECHNOLOGY
THEORY OF MACHINES (2151902)
Active Learning Assignment
On
MECHANICAL DEPARTMENT
FRICTIONAL CLUCHES
PREPAIRED BY:
MANAV SONANI
(140120119223)
CHANDRESH SUTHAR (140120119229)
GOVIND TADE
(140120119230)
GUIDED BY:
PROF. VIPAL PANCHAL
2. CONTENT
• Introduction to clutch
• Types of clutch
• Disc clutch
Single plate clutch
Multi plate clutch
• Cone clutch
• Centrifugal clutch
3. WHAT IS CLUTCHES ?
•A Clutch is a mechanical device that engages and disengages the
power transmission , especially from driving shaft to driven shaft.
•In the simplest application, clutches connect and disconnect two
rotating shafts (drive shafts or line shafts). In these devices, one
shaft is typically attached to an engine or other power unit (the
driving member) while the other shaft (the driven member) provides
output power for work.
4. TYPES OF CLUTCHES
1)Mechanical clutches
2)Pneumatic clutches
3)Hydraulic clutches
4)Electromagnetic clutches
Mechanical clutches
1)Positive contact clutches
i. jaw clutches
ii.toothed clutches
2)Friction clutches
Disc clutches
• Single plate clutches
• Multi plate clutches
Cone clutches
Centrifugal clutches
7. USED IN CARS AND LIGHT VEHICLES.
IT HAS ONLY ONE CLUTCH PLATE WHICH IS MOUNTED ON
THE SPLINES OF THE CLUTCH SHAFT.
WHEN CLUTCH IS IN ENGAGED POSITION, THE CLUTCH
PLATE REMAINS GRIPPED BETWEEN FLYWHEEL AND
PRESSURE PLATE. FRICTION LININGS ARE PROVIDED ON BOTH
THE SIDES OF CLUTCH PLATE.
8. Single Plate Clutch
•W=total axial load
•R1=External radius of clutch plate
•R2=internal radius of the clutch plate
•P=intensity of pressure between contacting surfaces.
•µ=coefficient of friction between contacting surfaces
1R
1R
9. Single Plate Clutch
•Consider a elemental ring of radius ‘r’ and
thickness δr on the contacting surface.
therefore,
•Area of the ring on contacting surface is,
•Axial load on the ring is,
δW=pressure×Area of the ring
δrr2πpδW ×=
10. Single Plate Clutch
•Frictional resistance offered by ring is,
•Frictional torque acting on the ring is,
δWμFr =
δrrpμ2πδr)r2πμ(pFr ==
r
2
r
rr
δrpμ2πδr.rrpμ2πT
rFT
==
=
11. Single Plate Clutch
•Torque transmitted by single plate clutch is
obtained by considering following two
assumptions
(a)uniform pressure theory
(b)uniform wear theory
12. Single Plate Clutch
(a)uniform pressure theory:
•Assuming that the intensity of pressure over the
entire contacting surface area is constant,
•Total torque transmitted by single plate clutch
can be obtain by integrating Equation
Then, p=constant
( )2
2
2
1 RRπ
W
areasurfacecontacting
load
p
−
==
13. Single Plate Clutch
•(1)within limit R2 to R1 we
[ p=Constant]∵
∫∫ =
1
2
R
R
2
T
0
r δrrpμ2πΤ
∫∫ =
1
2
R
R
2
T
0
r δrrpμ2πΤ
( )3
2
3
1
R
R
3
RRpμπ
3
2
3
r
pμ2πΤ
2
1
−=
=
15. Single Plate Clutch
(b) Uniform Wear Theory
•In this theory, we are considering that wear
which take place is uniform over the entire
contacting surface i.e.
P.r=constant
P.r=C
P=C/r …...(3)
16. Single Plate Clutch
•Axial load acting on the ring is
δW=p 2π r δr
δW=2 π C δr …(4)
•Integrating above Equation(4) within limit we get,
δrC2π
r
C
δW =
∫ ∫=
w
0
R
R
1
2
δrC2πδW
17. Single Plate Clutch
•We know that frictional torque acting on ring is,
……….(5)
…….(6)
[ ] ( )
( )21
21
R
R
RR2π
W
C
RRC2rC2πW 1
2
−
=
−== π
δrrCμ2πΤδrr
r
C
μπ2Τ
δrrpμ2πΤ
r
2
r
2
r
===
=
18. Single Plate Clutch
•Torque transmitted by single plate clutch can be
obtain by integrating the Equation (4 ) within the
limit R2 to R1 we get,
( )
2
RR
Cμ2π
2
r
Cμ2πΤ
δrrCμ2πΤ
δrrCμ2πΤ
2
2
2
1
R
R
2
R
R
T
0
r
R
R
T
0
r
1
2
2
2
2
2
−
=
=
=
=
∫∫
∫∫
19. Single Plate Clutch
•This is the torque transmitted by single plate
due to friction considering uniform wear theory.
( )
( )
( )
( )
μWπ
2
1
Τ
RR
RR
μWπ
2
1
Τ
RR
RR2π
W
μπΤ
21
2
2
2
1
2
2
2
1
21
=
−
−
=
−×
−
=
20. Single Plate Clutch
•Power transmitted by single plate clutch is
given by,
rpminshaftofSpeedNwhere,
Watt
60
NΤ2π
P
ΤωP
=
=
=
21. MULTIPLATE CLUTCH
Multi-plate clutch consists of more than one clutch plates
contrary to single plate clutch which consists of only one plate.
Friction surfaces are made in case of multi-plate clutch. Due to
increased number of friction surfaces, a multi-plate clutch can
transmit large torque.
24. Multiplate Clutch
Notes:
•In case of new clutch ,the intensity of pressure is uniform
along the surface of clutch but in case of old clutch
uniform theory is more correct.
•For single plate clutch normally both sides of the plate
are effective .there for single plate clutch has two pairs of
contacting surface i.e. n=2.
•In actual practice, usually the theory of uniform wear is
used in analysis of clutch.
25. •Intensity of pressure is maximum at the inner radius R2 of the
friction or contact surface,
•Intensity of pressure is minimum at the inner radius R1 of the
friction or contact surface,
2
max2max
R
C
PORCRP ==×
1
max1max
R
C
PORCRP ==×
26. In mutilate disc clutch
no of disc on driving shaft
no of disc on driven shaft
So no. of pairs in contact,
1nnn 21 −+=
=1n
=2n
28. CONE CLUTCH
• A cone clutch serves the same purpose as a disk or
plate clutch. However, instead of mating two spinning
disks, the cone clutch uses two conical surfaces to
transmit friction and torque.The cone clutch transfers a
higher torque than plate or disk clutches of the same
size due to the wedging action and increased surface
area.
29. CONE CLUTCH
• Cone clutches are generally now only used in low peripheral
speed applications although they were once common in
automobiles and other combustion engine transmissions.They
are usually now confined to very specialist transmissions in
racing, rallying, or in extreme off-road vehicles, although they are
common in power boats.
38. CENTRIFUGAL CLUTCH
• A centrifugal clutch works on the principle of centrifugal force.
• The clutch's purpose is to disengage when the engine is idling so
that the chain does not move .
• These clutches are particularly useful in internal combustion
engines, which can not be started under load.
39. •The clutch consists of three parts:
•An outer drum that turns freely - This drum includes
a sprocket that engages the chain. When the drum
turns, the chain turns.
•A centre shaft attached directly to the engine's
crankshaft - If the engine is turning, so is the shaft.
•A pair of cylindrical clutch weights attached to the
centre shaft, along with a spring that keeps them
retracted against the shaft
CENTRIFUGAL CLUTCH
40. • There are several advantages to a centrifugal clutch
• It is automatic. (In a car with a manual
transmission, you need a clutch pedal. A centrifugal
clutch doesn't.)
• It slips automatically to avoid stalling the engine.
(In a car, the driver must slip the clutch.)
• Once the engine is spinning fast enough, there is no
slip in the clutch.
• It lasts forever.
CENTRIFUGAL CLUTCH